2652-65-5Relevant articles and documents
Photochemistry of 9-fluorenone oxime phenylglyoxylate: A combined TRIR, TREPR and ab initio study
Kolano, Christoph,Bucher, Goetz,Wenk, Hans Henning,Jaeger, Martin,Schade, Olaf,Sander, Wolfram
, p. 207 - 214 (2004)
The photochemistry of 9-fluorenone oxime phenylglyoxylate (1) in tetrachloromethane was investigated by a variety of time-resolved methods [STEP-SCAN TRIR and time-resolved EPR (TREPR)]. Photolysis of 1 yields the benzoyl radical, carbon dioxide and the f
First unequivocal identification of the critical acyl radicals from the anti-tuberculosis drug isoniazid and its hydrazide analogs by complementary applications of ESR spin-trapping and HPLC/MS methods
Huang, Chun-Hua,Mao, Li,Qin, Li,Shao, Bo,Zhu, Ben-Zhan
, p. 1 - 8 (2020)
The carbon-centered isonicotinic acyl radical of isoniazid (INH), a widely-used frontline anti-tuberculosis drug, has been considered to play a critical role in inhibiting Mycobacterium tuberculosis, but not fully identified. Here we show that this radical intermediate can be unequivocally characterized by complementary applications of ESR spin-trapping and HPLC/MS methods by employing N-tert-butyl-α-phenylnitrone (PBN) as the suitable spin-trapping agent, which can form the most stable radical adduct. More importantly, for the first time, analogous carbon-centered acyl radicals and their respective NAD+ adducts have also been detected and identified from its two isomers (nicotinic acid hydrazide and 2-pyridinecarbohydrazide) and benzhydrazide which are structurally-related to INH, but not by 2-chloroisonicotinohydrazide. This study represents the first unequivocal identification of the carbon-centered acyl radicals of INH and other hydrazide analogs by both ESR spin-trapping and HPLC/MS methods, which may have broad biomedical and toxicological significance for future research for more efficient hydrazide anti-tuberculosis drugs.
Gas-Phase Reactions of Phenyl Radicals with Aromatic Molecules
Fahr, Askar,Stein, S. E.
, p. 4951 - 4955 (1988)
Relative rates of reactions of phenyl radicals with a series of aromatic and polycyclic aromatic compounds are reported.Most studies were done in static reactors at 450 deg C using diphenyl diketone (benzil) as the phenyl radical source.Reactions with the following molecules are reported: benzene, toluene, p-xylene, 1,3,5-trimethylbenzene, phenol, bromobenzene, naphthalene, biphenyl, anthracene, 9-methylanthracene, and triphenylene.For reactions with substituted benzenes, H abstraction is the dominant reaction.Relative rates of phenylation at different sites do not closely follow established trends for rates of radical attack.It is proposed that these deviations are primarily due to a dependence of the degree of reversibility on the specific site of phenylation.These studies also show that the rates of phenyl and H-atom migration around the ring in adduct radicals are slow relative to dissociation.Also, by use of these results to link literature rate data from high and low temperatures, a rate expression for H abstraction from p-xylene by phenyl of 109.6 exp(-4.4 kcal/RT) M-1 s-1 is derived.
Photogeneration and reactivity of acyl nitroso compounds
Evans, Anthony S.,Cohen, Andrew D.,Gurard-Levin, Zachary A.,Kebede, Naod,Celius, Tevye C.,Miceli, Alexander P.,Toscano, John P.
scheme or table, p. 130 - 138 (2011/04/23)
Acyl nitroso compounds have been generated by photolysis of several different classes of precursors including 9,10-dimethylanthracene adducts, nitrodiazo compounds, and 1,2,4-oxadiazole-4-oxides. Consideration of the nitronate-like resonance structure of nitrodiazo compounds led to an examination of the photochemistry of nitronates with -leaving groups. Photolysis of such nitronates has been shown to generate an acyl nitroso species along with a carbene intermediate. Nanosecond time-resolved infrared (TRIR) spectroscopy has been used to detect photogenerated acyl nitroso compounds directly and to examine their reaction kinetics with amines and thiols. The mechanism of acyl nitroso aminolysis by primary amines involves general base catalysis, while the mechanism of aminolysis by secondary amines is strictly bimolecular. Thiols do not seem to be reactive with acyl nitroso compounds on the microsecond time scale, but thiolates are quite reactive. The reaction between benzoyl nitroside and an organic-soluble thiolate, tetrabutylammonium dodecanethiolate, proceeds via a proposed tetrahedral intermediate, which is observable by TRIR spectroscopy.
Effect of nitroxide radicals on chemically induced dynamic electron polarization of spin-correlated radical pairs in aqueous micellar solutions of sodium dodecyl sulfate
Gorelik,Tarasov,Shakirov,Bagryanskaya
experimental part, p. 1416 - 1427 (2009/09/30)
The multispin systems consisting of spin-correlated radical pairs (SCRPs) and stable nitroxide radicals, localized in micelles of sodium dodecyl sulfate (SDS), were studied by ESR and pulse laser photolysis techniques. In all the systems studied, the stab
